I'll take a stab at it.
Some of the early research—You're quoting the Perry preschool project, which was in the United States, and that was for severely disadvantaged children. They did come up with a figure of $7 or $8 return for every dollar invested. Gord Cleveland did a cost-benefit analysis that led him to suggest that for every dollar you invest in child care, you get $2 into the economy.
We haven't done that sort of research. Obviously it's well accepted that good-quality early learning and child care programs are good for children, but one of the most important aspects is also good parenting. You can't look at programs in isolation; many factors contribute to child development.